Roller core drill



Eek. 26. 1924.

J. D. PACE ROLLER CORE DRILL F iled Nov. 30. 1921 A HOB/VH8 PatentedFeb. 26, 192d.

l i E x:

JEFFERSON DAVIS PACE, OF SHREVEPORT, LOUISIANA.

ROLLER CORE DRILL.

Application filed November 30, 1921.

To all whom it may concern:

Be it known that I, JEFFERSON DAVIS PACE, a citizen of the UnitedStates, and a resident of Shreveport, in the parish of Caddo and Stateof Louisiana, have invented certain new and useful Improvements inRoller Core Drills, of which the following is a specification.

My invention relates to improvements in well drills, and it consists inthe constructions, combinations and mode of operation herein describedand claimed.

One of the objects of the invention is to provide an improved bearingfor each roller cutter, shot being mixed with heavy grease by which itis lubricated, to render the grease mobile for the purpose of reachingthe bearing surfaces.

Other objects and advantages will appear in the following specification,reference being had to the accompanying drawing, in which Fig. 1 is avertical longitudinal section of a well drill embodying the improvedhearing for the roller cutters,

Fig. 2 is a sectional view illustratin how roller mountings may begripped y a blade-cutter drill, and

Fig. 3 is a detail perspective view of one of the roller holders and itsroller cutter. A drill rod 1 carries a coupling sleeve 2 whichterminates in brackets 3 upon which the bearing stems 4 of the conicalroller cutters 5 are mounted.

It is the bearing and lubricating means for the roller bits or cutters 5which constitutes one of the important features of the invention. Thestem 4 (referring only to one of the aforesaid devices, since both arealike) is threaded only at the exposed end so that a nut 6 may beapplied and secured by a cotter pin 6 so as to hold the stem or hollowbolt 4 in place. A shoulder 7 abuts a washer 8 and enables tighteningthe nut 6 firmly on the body or sleeve 2.

A threaded collar 9 holds the body 10 in place in the bit 5. The body 10has a flange 11 which extends beneath the collar 9. The concavity 12 isthe bottom of the recess inside of the bit 5, into which the collar 9 isscrewed and which receives the body of the stem. It is to be observedthat the collar 9 has spanner wrench holes 9 which enable the collar tobe screwed in place.

Serial No. 518,851.

A central recess 13 in the body 10, has a a plurality of radiatingapertures 14 through which some of the grease G is enabled to reach thebearing surfaces between the ,body 10 and collar 9. This is aheavy-bodied grease which is packed in the recessesinside of the bit.grease resists the entrance of moisture and other foreign. substancesinto the interior of the bit and its associated parts. Also, beingheavy-bodied, the grease requires something to render it mobile in orderthat theapertures 14 maybe penetrated and the bearing surfaces reached.

A suitable quantity of shot 15 is mixed with the grease G. The rapidrevolution of the bit 5 causes the shot to circulate in the grease andthereby render it sufficiently mobile to accomplish the purpose stated.The bits 5 are separated so as to leave a central passage which leadsinto the core tube 16. This particular type of drill is adapted to cutthrough rock or other hard formation.

As the drill cuts deeper into the rock, a central core gradually risesinto the tube 16 by virtue of the fact that the material is cut away ina circular path the width of the bit 5, leaving the central core to risein the tube and past the slips or grippers 17. At suitable intervals thedrill 1 is removed from the bore. The tapering slips will then ride downthe inclined walls of the recess 18 which contains them, and thus securea firm hold on the core. The core breaks off and thus the drill containsa. sample of the formation through which the drilling operation isperformed.

The slips have teeth 19 on the inside so as to secure a hold on thecore. A spring wire 20 holds the slips together and prevents them fromdropping out of the bottom. This spring wire occupies a groove formed inthe slips, this groove, however, being shallow so that the wire extendsabove the surface of the slips. The outstanding portion of the springwire furnishes a bearing which engages the wall of the recess 18 andthereby causes a more prompt closure of the slips upon a core samplethan would be possible were the direct engagement of the outsides of theslips with the recess wall depended upon. A top 21 closes the top of thetube 16. This top has a plurality of openings 22 through which water orother fluids may Being heavy-bodied, the

which may be caught by a fishing tool should it becomenecessary to pull*the drill out of the casing or bore.

A circulation of water is maintained so as to keep the bit 5 clear. Thiswater passes down inside of the drill rod l, through Wash holes 24 inthe coupling sleeve 2 and up around the'outside of the drill rod.

The modification in Figure 2 illustrates the adaptation of bits orcutters which are constructed in accordance with the invention, to adrill such as-is disclosed. in my Patent 1,351,003 granted August 24,1920. Instead of using the coupling sleeve 2 for the purpose of securingcutte'r blades on theblock or body 25, they are employed to clampholders 26 which, like the coupling 2 in Fig. 1, have brackets 3 uponwhich the bearing stems 4 and bits 5 are mounted. These holders haveinclined surfaces27 against which a corresponding surface on the insideof the sleeve 2 bears and produces a wedging action to force the heads28 into recesses 29 at the base of the block 25. This block includes anextension 30 against which the inner side of the holders 26 havebearing.

-1. A drill having a rotary cutter, recessed bearing means for thecutter with radial openings, and shot mixed with grease packed in therecess rendering the grease mobile for penetration of the openings tothe bearing I surfaces.

2. A drill having supporting means, a rotary cutter and a bearing stemrotatably mounting the cutter on the supporting means, including anenlarged body presenting a shoulder against the supporting means,

and havinga recess with radial apertures leading to bearing surfaces,and grease packed in the recess mixed with shot to cause the penetrationof the apertures by the grease when the cutter rotates.

3. A drill having-supporting means, a rotary cutter with a recess, abearing stem having a body presenting a shoulder against the supportingmeans when the stem is secured therein, and having a recess with lateralopenings, a flange on the body, a collar fitted into the cutter recessto be engaged by the flange, and grease packedin the cutter and bodyrecesses, mixed with shot to agitate the grease causing its entranceinto the opening to reach the ,"bearing surfaces.

4. A well drill having a coupling sleeve provided with a taperingopening having an annular shoulder formed by a smaller opening whichenters the large part of the tapering opening, a core sample tube fittedinto the smaller opening, gripper slips situated in the tapering openingeach having a depression forming a circular groove when the slips areassembled, and resilient means fitted in said groove to keep the slipsto 'gether said means extending'above the surface of the slips so as 'tomake contact with the wall of the tapering opening and thereby insure aprompt closure of the slips upon a downward motion in said opening.

- JEFFERSON DAVIS PACE.

